Reaserch On Synthetical Utilization Of Tobacco Stalk And Municipal Hogwash By Compost

Huge amounts of tobacco stem was produced in flue-cured leaf tobacco production,the methods of traditional incineration and discard tobacco stem dispose led toproblems as wasting of resources, and also caused air and water pollution. Compostwas an effcient way of disposal and synthetical utilization of solid waste, and wasaccording with the principles of resourcefulness, minimization and harmlessness.In this paper, the organic matter and nutrient losses of tobacco stem after incinerationdispose were tested. Based on the compost test with tobacco stem and municipalhogwash, nutrient release characteristics together with application effect of compostproduct in different composting period were conducted in crop cultured experiment.The result provided a new way for synthetical utilization of tobacco stem andmunicipal hogwash.1．The dry matter and nutrient losses of tobacco stem caused by incinerationAfter carbonization, the dry matter loss of tobacco stem was 57．5%, the loss of C, N,P and K was 39．7%, 88．4%, 13．0% and 8．9% respectively. After incineration, the drymatter loss of tobacco stem was 94．9%, the loss of C, N, P and K was 99．6%, 99．8%,89．0% and 17．0% respectively. Much more losses of dry matter and nutrient werecaused by incineration of tobacco stem.2．The utilization of tobacco stem by compostAt composting 2 d, the compost temperature during tobacco stem + municipalhogwash and tobacco stem + urea composting both reached peak (58℃and 54℃respctively), and then down to the room tempreture. The moisture content of compostwas showed a decreased tendency, and finally droped on a steady state (32．8% and28．6% respctively). After about 20 d, the pH of compose ascended to a maximumvalue of 8．55 and 8．45 respectively, and decreased gradually to about 8．0．NH₄⁺-Nwas increased first and then decreased, NO₃^--N was showed upward trends, NH₄⁺-N/NO₃^--N value was showed descending trend and reached a steady rate of about 0．13．Culture experiment with final stage composting product showed the GI up to 86% and85%. The total amino acids of tobacco stem + municipal hogwash compostingproduct was higher than that of tobacco stem + urea composting.3．The effect of composting product with diffrent compost maturity on soilnutrientsThe content of hydrolytic nitrogen, available phosphate and available potassium in the soil applying compost product of higher maturity (composted for 50 d and 70 d) weremore than that of lower maturity (composted for 0 d, 15 d and 30 d). The hydrolyticnitrogen reached the peak (1．73 and 1．80 times of the initional value) in the soilapplying compost product of 50 d and 70 d. The hydrolytic nitrogen in the soilapplying compost product of lower maturity kept always at a ralatively lower value.Applying under-composed product, the available phosphate in soil was in-creaseedslightly, and showed no increasing tendency after about 20 d. Applying productcomposting for 50 d and 70 d, the available phosphate in soil was the peak appearedat about 30 d, increased 52．0% and 63．8% respectively compared with the initionalvalue.Applying product composting for 0 d, 15 d and 30 d, the available potassium wasincreased slightly, and reached a steady value at about 30 d. Applying productcomposting for 50 d and 70 d, the available potassium in soil was the peak (465．1mg/kg and 471．1 mg) appeared at about 40 d and 30 d respectively.4．The cabbage quality cultured with composting product of diffrent compostmaturityAll of the tested items of cabagge cultured with soil applied with tobacco stem +municipal hogwash was the maximums. The plant height was 30．9 cm; nitratereductase enzyme activity was 6．45 ugNO₂-N/(g.Fw.h); chlorophyll a, chlorophyll b,chlorophyll and carotenoid (Car) was 0．92 mg.g^-1 FW, 0．50 mg.g^-1 FW, 1．42 mg.g^-1 FW and 0．35 mg.g^-1 FW respectively; biomass was 83．5 g per plant; total nitrogen,total phosphorus and total potassium of the cabagge were 4．85%, 0．55% and 8．30%respectively; the content of hydrolytic nitrogen, available phosphate and availablepotassium in the soil were 149．8 mg/kg,61．7 mg/kg and 388．0 mg/kg respectively.The result presented above proved that application of the tobacco stem + ureacomposted product could increase the yield and qulity of cabagge.